Prevent non-admin from editing single page

I’m working on several client sites in which I’m embedding content with iframe on single pages. This works of course, until the client comes along and opens that page in the visual editor.

I’m looking for a solution that would keep the client from being able to edit that page. The “lock-down pages” plugins prevent the slug/URL from being changed and the page from being deleted, but not from being opened or edited.

Is there a plugin that would prevent the page from appearing in the list of pages — at least for non-admins– but still appear in the menus?